In my opinion the best thing you can do about it is just - talk! Talk as much as possible, look for friends on the internet you can talk to via Skype etc. - the internet provides us great possibilities!
I had the same problem some time ago, I’d hardly ever spoken English before, at school - OK, but that was not “real talking”. Then I started talking to one American guy - not often, just from time to time - and the more I talked the more confident I was about it.
Just don’t be afraid of making mistakes, of stopping, of having to think about words…
I think there are two things among which has to be differed - the “active vocabulary” and the “passive vocabulary”. Passive vocabulary is the amount of words, phrases… you understand while reading or listening, the active is the vocabulary you are able to use while talking or writing. Your passive vocabulary usually is much wider than the passive (not only in English but also in your mother tongue!) which is only logical.
So don’t worry if you have to look for words while talking, you’ll see that you improve every day you’re talking.
I personally think that the first and usually easiest part of learning a language is understanding the written language. Second comes understanding the spoken language (I’m not talking about understanding different accents of course), third comes writing texts on your own - and the most difficult usually is talking. Might be different for different people and always depends how and where you learn the language (if you go to another country to learn the language there speaking usually is easier than writing for example) of course as well.
So all in all, Leedsana - talk as much as possible!!!
And by the way - there’s no reason for being sorry about your English, it’s good and you can make yourself understood, you can express yourself - so don’t worry about it!
 Sorry, I’ve only read now that you’re living in the UK, so forget some things I’ve written! Then it’s even easier to give you some advice - just go out, whenever possible, and try to meet people. Perhaps you can attend a course at an edult education centre or somewhere else about something you are interested in. If not, just go out of the house - perhaps you can find another mother sitting at a bench on a playground you can start talking to, perhaps… There are soooo many possibilities to talk when you’re living in the country where the language is spoken - just again, don’t worry about making mistakes, nearly nobody will laugh about you, most people will honour that you try using their language, that you WANT to speak their language - and then it doesn’t matter when/if there are some mistakes or you have to stop.